The Flying Star in Cygnus

 The fourteenth-closest star system is the double star 61 Cygni.  At a distance of 11.4 ly, this pair was nicknamed the "Flying Star" by Giuseppe Piazzi in 1792 because of its high proper motion of about 5 arcsec per year.  This was also the first star system to have its distance measured by trigonometric parallax, by Friedrich Wilhelm Bessel in 1838. The two stars, which are separated by 32 arcsec,  have magnitudes of 5.2 and 6.0 and a combined magnitude of 4.8.  This makes the star technically visible to the naked eye, under dark skies with good eyesight.

 I photographed the star Monday night, in the light of the first-quarter moon, using three lenses: Panasonic Leica 25mm f/1.4 (with softon filter), Rokinon 135mm f/2, and Asto-Tech AT80EDT refractor.

The constellation Cygnus and 61 Cygni (circled). Leica 25mm

 

61 Cygni resolved with the Rokinon 135mm lens

61 Cygni A + B.  AT80EDT refractor

The Milky Way core rising over Snowshoe Mtn.  Leica 25mm

The source of the blue sky, the first-quarter moon:

AT80EDT refractor

 

A nearby double star: Struve 2398

 Of the fifteen-nearest star systems, seven — almost half — are double or triple stars.  The fifteenth-closest star system is Struve 2398, at a distance of 11.49 ly.  It consists of two red-dwarf stars with magnitudes 8.9 and 9.7.  Struve 2398 is in the northern sky in the constellation Draco.  The image below shows its location relative to the Little Dipper.

Struve 2398 (circled), the 15th closest star system.

 The Little Dipper is on the left side of the frame, with Polaris in the lower-left corner.  A Panasonic Leica 25mm f/1.4 lens with a Hoya Softon filter was used to obtain this image in moonlight (hence the blue sky) on Saturday night.

A Rokinon 135mm f/2 lens provides a closer view:

Struve 2398 (circled). Rokinon 135mm f/2.  North is up.

Finally, an Astro-Tech AT80EDT 80mm f/6 telescope was used for an even closer view that shows this double star resolved into its two components:

Struve 2398 (middle). 2x enlargement.

 This image is a stack of three  exposures.  The two stars are separated by about 12 arcseconds.   The star toward the left of the frame is an unrelated background star.

On the same evening, even though the moon was up, I used the Leica 25mm lens to capture a shot of Scorpius rising over the southern end of Snowshoe Mountain:

 

Moon, Mercury, Milky Way

On Wednesday evening, 16 June, Mercury was still visible and accompanied by the crescent moon during twilight.

Mercury (circled) and the Moon.  Olympus 40-150mm f/4.

 

Mercury (center) 1:1 crop.  Olympus 40-150mm

Near midnight, long after the moon had set, I imaged the Milky Way with an OM 20mm f/1.4 lens.

3x3 median digital filter

 

Summer Triangle, 3x3 median digital filter

These are the same two scenes with a physical Hoya Sparkle-6 filter:

 

A more southerly view:

 The layers of green and purple airglow are mostly invisible to the unaided eye and simply present as a vague brightening toward the horizon.  When strong airglow is present the sky near the horizon is typically about 0.4 mpsas brighter than directly overhead.

Daytime occultation of Venus

 Yesterday at 12:52 pm MDT the waxing crescent Moon passed in front of the planet Venus.  The event was visible in full daylight.  I set up a 360mm f/6 scope on a ZWO AM3 mount and used the go-to function to find the Moon and Venus in the bright blue sky.

Venus moments before occultation

 

Occultation begins

Later that evening the crescent Moon and Venus neatly framed the Beehive Cluster (M44) over Bristol Head:
 

The Moon, M44, and Venus

Venus, Jupiter, Mercury

 Mercury reached its furthest elongation from the Sun yesterday.  Even so, it is a difficult planet to catch from this location between two mountain ridges.  There is only a short time between when it becomes dark enough to see Mercury and when it slips behind the mountain.  Last night this was at 9 pm.

 

Venus (top), Jupiter (middle), and Mercury (bottom)

These are two views, enlarged 2x, of Mercury dipping into the treeline:

 Near midnight on the same evening the sky brightness was measured at sqml=21.68 mpsas, a very good value.  The Milky Way was well positioned for photographs.

Sony A7iii + Laowa 15mm f/2

 A 3x3 median filter was applied to this image in post processing to suppress the faint stars and let the Milky Way stand out.

 

 

Milky Way roundup

 The new moon is today, 15 June.  There are only a couple days left before the waxing moon begins to wash out views of the Milky Way.  Here is a roundup of some images taken during the dark skies of the past week.

 

7Artisans 7.5mm f/2.8 fisheye.  3x3 median filter

Laowa 7.5mm f/2.  Sparkle-6 filter

Panasonic Leica 9mm f/1.7. Sparkle-6 filter

Panasonic Leica 12mm f/1.4, 3x3 median filter

Panasonic Leica 12mm f/1.4, Softon filter

Sony A7iii + Rokinon 135mm f/2 Nikon AE

Sony A7iii + Rokinon 135mm AE

Sony A7iii + Rokinon 135mm AE, 3x3 median filter

E-M5iii + Rokinon 135mm f/2

This last image shows the star Antares (on the left), and the two globular clusters NGC 6144 (middle) and M4 (right).

Some nearby stars

 The second, third, and fourth nearest star systems are currently visible (with optical aid) in the late evening after twilight.  They are: Barnard's Star (second), Wolf 359 (third), and Lalande 21185 (fourth).  The following table shows the particulars: 

Some nearby stars in the evening sky

Rank	Name	distance (ly)	magnitude
2	Barnard's Star	5.96	9.5
3	Wolf 359	7.86	13.4
4	Lalande 21185	8.30	7.5
11	Ross 128	11.01	11.1
30	Wolf 1061	13.43	10.1

A couple of other nearby stars are included in this table because they are currently positioned for viewing as well.  These five stars are all red dwarfs, and all of them are too faint to be seen with the unaided eye.  In case you are wondering, the fifth-nearest star system is Sirius, which is also the brightest star in the night sky, and currently not visible in the evening.

 Three of these stars are located in the western sky: 

Ross 128 (left), Wolf 359 (middle), Lalande 21185 (right)

The other two are located in the east, preceding the rising Milky Way:

Barnard's Star (left), Wolf 1061 (right)

 The two images above were obtained with an Olympus E-M1iii camera and Panasonic Leica 9mm f/1.7 lens with a Hoya Sparkle filter.

The next set of images of the individual stars were obtained with an Olympus E-M5iii camera and a Rokinon 135mm f/2 lens.

Barnard's Star (circled). Second closest star system.

Wolf 359 (circled). Third closest star system.

Lalande 21185 (circled). Fourth closest star system.

Ross 128 (circled). 11th.

Wolf 1061 (circled). 30th.

The globular star cluster M107 appears down and to the left of Wolf 1061.